The conventional archery bow comprises an elongate member which can be bent into an arc and which has resiliency therein which urges the elongate member to return toward a straight condition. The conventional bow includes a bow string joined to the ends of the elongate member. As the bow string of a conventional bow is drawn, the ratio of the drawn distance to the draw force is nearly linear until a point is reached at which the draw force rises much more rapidly than the draw distance. The point at which this rapid increase in force occurs is related to the length of the elongate member which forms the bow, in that the point is reached after only a short draw of the bow string in a short bow. Thus, it has been considered desirable to employ a relatively long bow so that significant values of energy can be established in the bow without requiring large forces.
However, short compact bows are particularly desirable and advantageous in minimizing space requirements and in permitting ease in carrying of the bow. A small compact archery bow is particularly advantageous in hunting, as the hunter moves through closely positioned trees, underbrush and the like.
It is therefore an object of this invention to provide an archery bow which is relatively small and compact and which is capable of applying significant force to an arrow in the launching thereof.
It is another object of this invention to provide such an archery bow which is capable of high energy storage.
Another object of this invention is to provide such an archery bow in which bow limbs are rotated through large angles without significant loss of effective conversion of bow string draw force to bow limb torque, thus permitting the use of bow limbs which are relatively short.
Another object of this invention is to provide such an archery bow within which the force required to maintain the bow string in full draw position is less than the peak draw force.
Another object of this invention is to provide such an archery bow which can be constructed as a cross-bow type or as a long bow type.
It is another object of this invention to provide such an archery bow in which a single drive motor may be employed.
Another object of this invention is to provide such an archery bow in which the stored energy available in a drive motor can be readily adjusted.
It is another object of this invention to provide such an archery bow in which the ratio of draw distance to draw force can be readily adjusted.
Another object of this invention is to provide such an archery bow in which movement of a plurality of limbs is automatically synchronized.
Another object of this invention is to provide such an archery bow in which the bow span at full draw position is significantly less than the bow span in the braced or relaxed bow condition.
Other objects and advantages of this invention reside in the construction of parts, the combination thereof, the method of production, and the mode of operation, as will become more apparent from the following description.